The wavering health and tattered reputation of convicted child abuser Rolf Harris are all that stand between him and a decade in jail overnight.

On Monday, he was found guilty of the sexual assault of four girls aged between 8 and 19. On Friday in London his lawyers were due to argue that, despite his guilt, he did not deserve to leave Southwark Crown Court in a prison van.

Harris faced a theoretical sentence of decades in jail – essentially the rest of his life – but legal experts predicted a likely term of up to 10 years.

After the 84-year-old Australian entertainer was found guilty, trial judge Nigel Sweeney warned him that a jail sentence was likely.

“Given the conviction on all 12 counts, it's inevitable that the type of sentence uppermost in the court's mind is a custodial sentence,” the judge said.

Mr Justice Sweeney was due to consider new medical reports on Harris, victim impact statements from the four women whom he assaulted as girls, and mitigating arguments from both defence and prosecution counsel, before passing sentence.

For the 12 counts of indecent assault, the judge is constrained by the maximum sentences at the time the crimes were committed – considerably lower than today. However within those limits he was free to impose a sentence according to modern attitudes as to the seriousness of the offence.

One of the counts carries a maximum five-year term, because the victim was under 13. A further three counts carry a maximum 10-year terms, because they occurred after 1985, when penalties were increased. And the rest carry a maximum of two years' jail each.

The judge may order any or all of the sentences to be served concurrently, to make the final sentence “just and proportionate”. Potential mitigating factors include the seriousness of each assault, the harm done to the victims, remorse and previous good character. Age and medical problems can also reduce a sentence, because they are considered to make jail more onerous.

During the trial, Harris said that 10 years ago he was diagnosed with diabetes, and had also suffered a "mini-stroke" during which he “couldn't put words together”.

He also had two stents put in to deal with heart problems.

During the trial, Harris' victims described the impact his assault had on them. The main complainant, a childhood friend of Harris' daughter, Bindi, was abused by Harris on at least four occasions before her 16th birthday, and once when she was 19.

She was scared of him and would drink “a shed-load” of gin to deal with the anxiety caused by his attacks. Her dependence on alcohol grew into full-blown addiction by her late 20s.

“I just felt dead,” she said. “I just became shy and scared, I got anxious about all sorts of things.”

She said she used alcohol to stop her panic attacks and anxiety, which she said were caused by “Rolf probably, what had gone on before, all the sexual stuff that had happened to me.”

She said she had stopped drinking in 2000 but still got panic attacks and anxiety that her doctor was trying to help her with, and she was taking medication for that.

If Harris is sentenced to jail he may, like sex offender Max Clifford, first be sent to the induction unit at the spartan, Victorian-era Wandsworth prison. Clifford was then moved to Littlehey jail in Cambridgeshire, which currently holds about 600 sex offenders. Adults in the prison must wear T-shirt and jeans, are allowed to watch free-to-air television and get a PlayStation.

However Harris may also end up at rural Leyhill Prison, a World War 2 military hospital in Gloucestershire converted into a jail for low-risk inmates. The prison has large botanical gardens and many prisoners work on the trees, lawns and organic vegetable crops– the prison has previously entered into several horticultural shows. It also has a "daycare centre" for the over-50s, called the "Lobster Pot", which aims to “provide purposeful activity for all older prisoners”, according to a government report.